Photochemistry in a soft-glass single-ring hollow-core photonic crystal fibre.

Ana M Cubillas,Bastian J M Etzold,Nicola Taccardi,Philip St J Russell,Tijmen G Euser,Peter Wasserscheid,Xin Jiang

doi:10.1039/c6an02144a

Abstract

A hollow-core photonic crystal fibre (HC-PCF), guided by photonic bandgap effects or anti-resonant reflection, offers strong light confinement and long photochemical interaction lengths in a microscale channel filled with a solvent of refractive index lower than that of glass (usually fused silica). These unique advantages have motivated its recent use as a highly efficient and versatile microreactor for liquid-phase photochemistry and catalysis. In this work, we use a single-ring HC-PCF made from a high-index soft glass, thus enabling photochemical experiments in higher index solvents. The optimized light-matter interaction in the fibre is used to strongly enhance the reaction rate in a proof-of-principle photolysis reaction in toluene.

Highlights

Photochemistry—the study of light-driven chemical reactions —plays an important role in nature, e.g., in photosynthesis and, at the same time, has found a wide range of applications in industry, technology, and medicine.[1]
We have recently shown that hollow-core photonic crystal fibres (HC-PCFs) can act as highly efficient microreactors for such studies.[2,3]
HC-PCF consists of a central hollowcore of diameter ∼20 μm, surrounded by a cladding formed by an array of hollow channels running along the entire length of the fibre.[4]

Summary

Introduction

Photochemistry—the study of light-driven chemical reactions —plays an important role in nature, e.g., in photosynthesis and, at the same time, has found a wide range of applications in industry, technology, and medicine.[1]. The use of single-ring ARR structures significantly reduces fabrication difficulties. In such fibres the central hollow core is surrounded by a ring of capillaries with a wall thickness from several hundred nm to a few μm. These capillaries act as offresonance Fabry–Pérot (FP) resonators that frustrate leakage of Recent studies have shown that, by careful design, higher order modes can be strongly suppressed in single-ring ARR HC-PCFs by a phase-matched coupling between higher-order core modes and leaky resonances in the surrounding capillaries.[8,9,10,11]

Methods

Results

Conclusion